Geometric model



Aug. 8, 1939. w. A` SPENCER GEOMETRICMODEL Filed July 29, 1937 mwfmm Patented Aug. 8, 1939 lJrufrt-.o STATES PMI-:NTY oFFicE GEOMETRIO MODEL Walter Arthur Spencer, Chicago, Ill.

Application July29, 1937, Serial No. 156,294 3 claims. (C1. 3534) This invention relates to models for visual education and more specically relates to the vconstruction .of geometric models.

In the teaching of many subjects, the student must be trained in space Vision. In many instances it is dii'licult for the student to visualize a three dimensional gure from aV two dimensional diagram in a textbook. Photographs .of three dimensional models are helpful but often result in a distortioned view that obscures rather than clarifies space vision.

It is therefore obvious that the best 4training in space imagination is available from a first hand inspection of thel actual model of the device.

It is then, an object of this invention, to standardize constructions Lof many geometric models.

A further object .of this invention lis to provide durable, neat and accurate models for visual education that do not confuse the student because `of mechanical constructions visible to the student.

A further object of this invention is to provide an improved, rigid, geometric model Ahaving .confusing mechanical structure .hidden from view.

Other and further objects of this invention will become apparent to those skilled in the art from the following detailed description of the annexed sheet of drawings Awhich discloses several embodiments of the invention. Itshould beunderstood, however, that the invention is not limited to the several models illustrated but sis applicable ,to the construction of many other .geometric models for visual education.

On the drawing:

Figure 1 `is .an isometric View of a geometric model according to this invention.

`Figure 21s a Vertical crossfsectionalyiew taken axially through the model shown in Figure 1.

Figure 3 is ,an enlarged horizontal cross-sectional vieW taken along the line III-III of Figure 2.

Figure 4 isa fragmentary view taken along the line IV--IV of Figure 2.

Figure 5 is an isometric view of another form of geometrcmodel according to this invention.

As `shown on the drawing: i .In Figures l and 2 the ,referencenumeral I0 designates a diskof wood, masonite, molded plastic or the like material forming the base of the model illustrated. The disk I0 has a bore y|| through the @center thereof as shown in Figure 2. The bore I|| is ycountersunk Aat thebottom as at .A` rod I3 .extends through thebore .l Land a nut I4 may be threaded Q11 the bottom 0f the rod ami seated in the c ountersunk portion of the bore as is shown. Obviously Aa head integral with the rod could be used in place of the nut I4.

The lower segment |5 of a hollow sphere des- 5 ignated generally by the reference numeral I6 has a hole I'I through the bottom thereof as shown in Figure 2 for receiving the rod I3 therethrough.

A sleeve I8 is disposed around the rod I3 Within 10 the segment I5. The sleeve |8 `is larger than the hole I'I of the segment I5 and abuts the segment.

A disk I9 of wood, masonite or molded plastic has a hole 20 through the center thereof for re- 15 ceiving the rod I3 therethrough. The disk I9 rests on top oi the sleeve I8 and is held in the segment I5 by means of screws or the like fastening devices 2| as shown in Figure 1.

A rectangular rigid sheet or board 22 of plastic material, Celluloid, glazed paperboard or the like, has a hole 23 for receiving the rod I3 therethrough. The sheet 22 is disposed on top of the disk 9 and extends beyond the circumference of the ball member I6. 25

A second disk 24 is` disposed on top of the sheet 22. The diskl 24 has a hole `2 5 through the center thereof for receiving the rod 3 therethrough.

. A second sleeve 26 i s disposed around the rod 13 above the disk 2 4 and the top segment 2l 30 of the sphere I6 isdisposed over the disk and secured thereto by means of screws such as 42 3 asshown in Fig.1. -The segment 2 'I has a hole ,2 9 in Vthe Ytop thereofqfor receiving the rod I3 therethrough.

'Ihe sleeves I8 and 26, disposed around the rod I3, hold the sphere I6 in fixed relation on the rod and at the same time `reinforce the interior of the hollow sphere against collapse.

A third sleeve .30 is .disposed around the rod I3 above the segment 21 of the sphere It and abuts the segment 2'I. r

The lower segment 3| of a solid smaller sphere 32 `has a bore 33 therethrough and is disposed around the rod I3 above `the sleeve 30. The sleeve 45 3D holds the segment 3| in spaced relation above the sphere IB.

A second sheet or board 34 has a hole 35 therethrough for receiving the rod I3 and is disposed on the segment 3| as shown `in Figure 2.

The top segment 36 of the sphere 32 has a hole 31 therethrough for receiving the rod I3 and is disposed on top ofthe sheet 34.

A fourth sleeve T38 is disposedaround the rod I3 above the segment 36 of the sphere 32 and abuts this segment,

A metal disk 39 is disposed around the top portion of the rod I3 and rests on top of the sleeve 38. As best shown in Figure 3, the disk 39 has a plurality of equally spaced notches 40 formed in the periphery thereof for the purpose rto be hereinafter described.

An ornamental cover 4I is threaded on the top of the rod I3. The cover 4I has an integral annular flange 42 adaptedv to circumscribe the Vdisk 39.

A third rigid sheet 43 bisects opposite endsofv the sheets 22 and 34 as best shown in Figure 1. For example, the sheet 34 can pass through a slot formed in the upper edge of the sheet'43l while the sheet 43 can pass through a slot formed in the sheet 22. segment 21 ofthe sphere I6 by means of a bolt 44 tapped into the segment 21. Likewise, the sheet 43 can be secured to the lower segment 3| of the spherel 32 bymeans of a bolt 45 threaded into thesegment 3l. Y

From the above description, it should beV understood that the single rod I3 supports the spheres and sheets representing planes from the single base I while the various sleeves hold the members on the rod in proper spaced relation.

A single piece of strand material is laced between the disk 39 and the base IU of the model to form the outline of a cone. As best shown in Figure Y4, the base Il) has an annular groove 46 formed in the bottom thereof in spaced relation from its outer periphery. Small holes 41 are drilled through the base or disk I0 in communication with the groove 46.

Strand material 48 such as cat gut, string, wire,

Y or the like material is threaded through the holes 41 and over the disk 39; The strand material 48 is hooked in the grooves or slots 40 formed in the disk 39 and is so threaded as to pass from one s'ide of the disk over the top thereof to a notch or groove 40 on the other side thereof as best shown in Figure 3. The notches 40 are aligned with the holes 41 in the base I0 so that the strands 48 between the top disk and the base will converg symmetrically to outline a cone.

The strand material 48 passes through holes 22a, 34a and'43a provided in the sheets 22, 34 and 43. These holes are aligned with the holes 41 in the base I0 and the notches 4U in the disk In Stringing the strand material to -dene the cone one end thereof mayv be knotted While the other end is threaded through a hole 41 to pull the knot into the groove 46. The free end is then threaded over the disk 39 to the opposite side thereof and downward tothe base I0 .where it is looped under the base as shown in Figure 4 with the looped portion disposed in thegroove 46. This manner of threading the model makes possible the use of a single piece of strand material and greatly simplifies the construction.

The flange member 42 covers the strand material 48 looped over the disk 39 and the ornamental cover 4I tapers toa point so as to continue the continuity of the cone defined by the strand material. A

A covering memberor disk 50 asbest shown in Figures 2 and 4 is secured onto thebottom of the base I0 by means of screws such as 5I. This covering member 50 provides a smooth base for the model and is coextensive with the base so as to cover the looped strand material in the groove 46 in the base.

The sheet 43 is secured to the The ligure dened by the intersection of the sloping sheet 43 with the cone outlined by the strand material 48 can be marked on the sheet 43 as shown at 52, thereby clearly outlining the curve or figure obtained by the intersection of the plane defined by the sheet 43 with the cone defined by the strand material 48.

In the modication illustrated in Figure 5, disks 60 and 6I of rigid material such as wood, molded plastic or the like material receive the ends of rods 62 and 63 therethrough on diametrically opposed sides thereof. The rods 62 and 63 are seated in countersunk bores similar to the bore I I defined in Figure 2. Nuts may be threaded on the ends of the rods in a countersunk portion of the bores in the same manner in which nut I4 is secured on the rod I3 in the countersunk portion I2 of the bore I I of the structure in Figure 2.

The disks 60 and 6I are held in spaced relation by nuts such as4 64 threaded on the rods 62 and 63 against the facing sides' of the disks. Instead of nuts 64, sleeves such as I8 can be vdisposed around the rods 62 and 63 to hold the disks 60 and 6I in spaced relation.

The disks have a plurality of holes such as 65 therethrough near their outer peripheries and strand material 66 is threaded betwen the disks through the holes 65 to dene the desired geometric gure. The disks may be provided with annular grooves such as the groove 46 of the disk I0 described in the modification shown in Figure 4.

Plaster of Paris or dental impression plaster castings 61 and 68 are supported respectively on the disks 60 and 6I to define hyperboloids, paraboloids or other mathematical surfaces within the figure defined by the strand material 66.

Cover disks 69 and 1U are secured to the disks 60 and 6I respectively to cover the strand material looped around the disks and to hide the construction of the model from view. 'Ihese cover disks 69 and 10 can be secured to the disks 60 and 6I by means of screws such as 1I.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon .otherwise than necessitated by the prior art.

I claim as my invention:

1.. A geometric model comprising a disk-like base having a countersunk bore through the center thereof and an annular groove formed in the bottom thereof .lin spaced relation from the periphery of the disk,Y a metal rod extending through the bore and having a head seatedrin the countersunk part of the bore, a spherical member disposed around said rod above the base, said spherical member being formed of two segments, a sheet member disposed between the segments and projecting from the spherical member, a sleeve disposed around the rod abutting the top of the 'spherical member, a second spherical member disposed around the rod on top of said sleeve, said second spherical member being formed in two-segments, a rigid sheet disposed between the segments and projecting therefrom, a second sleeve disposed around the rod above said second spherical member, a disk supported on said sleeve around the top portion of the rod, strand material laced between thedisks and the base to dene the outline of a cone, cover devices for the base and the disks and a third 751 rigid sheet disposed around the rod between the spherical members thereon and secured to said spherical members, said third sheet intersecting the rst and second sheets.

2.' A device for visual education comprising a base having a central countersunk bore therethrough, a rod extending through said bore having a head portion engaging the base, a support receiving the top portion of the rod, strand material laced between the support and base over the top of the support and under the bottom of the base, covering members` disposed over the support and under the base to cover the strand material, a member disposed around said rod and extending at least to each run of said strand material between the base and support, to define in cooperation with said runs the outline of a geometric gure, and means disposed around said rod for holding said support and said member in spaced relation from each other and from the base.

3. A geometric model comprising a circular base having a countersunk bore through the center portion thereof, an annular groove in the bottom of the base'in spaced relation from the outer periphery thereof, said base having a plurality of vertical holes therethrough communicating with said annular groove, a rod extending upwardly from said base and having a head portion seated in said bore, a disk having a notched periphery disposed around said rod near the top thereof, said disk being smaller than said base, strand material threaded through said holes and laced through the notches of said disk for dening the outline of a. cone, a cover member disposed oVer the disk, a second cover member mounted under'the base, a spherical member disposed around said rod and extending laterally at least to said strand material to define in cooperation with the latter the outline of a geometric gure, and sleeves surrounding the rod for holding the spherical member and the disk in spaced relation from each other and from the base.

WALTER ARTHUR SPENCER. 

